My Yanmar 4JH3-te needs a rebuild?

[hpeer]

4JH4-TE with 1,780 hours. We are getting ready to head into Carribean so I had a Yanmar mech do a 2,000 hour check up which included removing and examining the heat exchanger. We bought the boat with about 800 hours on the engine.

What came out of the heat exchanger was an entire impeller, in about 11 bits. The PO apparently ate an impeller and then did nothing. I never noticed any cooling problems or overheating.

[jimbunyard]

400 on all cylinders would generally mean no need to rebuild. I'd try adjusting the valves (go a tad loose) and remove the breather from the turbo in a trouble-shooting effort...vent the breather line into a soda bottle or some such thing if it makes a mess.

If your oil consumption drops, either leave the breather unconnected (blocking off the fitting at the turbo!) or find and correct the problem with excessive oil in the breathing system.

Are you sure you have the right dipstick, and are using the correct amount of oil?

Running an engine a quart low if the engine holds 2-3 gallons will not hurt the engine, and may reduce or end excessive oil consumption.

There should be some crankcase pressure, but not a lot...

[SeaBreeze-1]

You mention that the oil you're using is Rotella 15-40. That's the same as what I use in my Yanmar but, I'm operating in The Great Lakes and St. Lawrence Seaway. My mechanic has suggested that if I choose to sail further south to warmer climates, I should keep an eye on possible oil consumption and "when" that's occurs, switch over to a straight 30 weight oil. If that is the case, it's possible that the average temperatures where you are operating are simply a little too warm for multi-grade oil. Why not try an oil change with straight 30 weight and see if that makes any difference at all. Unless there are other causes for concern, it certainly won't hurt and could save you a whole world of pain and expense.

[CascadeThumper]

Originally Posted by jrobert890

Hi Folks, I'll start by apologizing for the long post.



I'm sure everyone is looking forward to the holidays and the long cold winter . I just bought a new boat (new for me anyway) in July and on my 2 day trip home after she was launched I had to add about a quart of oil every 6 hours. I know I will take a lot of heat for this, and I should, but I didn't have a diesel mechanic look at the engine during the survey. I am trusting and a bit naive sometimes. The engine starts right up and runs well. There is a little smoke while running, but not alot, at least I don't think so. I was advised by a few mechanics that it could be stuck rings from sitting for 1.5 years, or fuel lift pump diaphram failure or turbo seal. I was worried, but I still had hope. I took a few trips in the summer and hoped the engine would improve. I'm still topping up the engine with 1 qt/6 hrs. Well before haul out last week, the yard finally did a diagnostic. The yard said that engine doesn't have a fuel lift pump diaphram, so that is out. The mechanic did a compression test and it was 400 psi across all 4 cylinders. He added oil to the cylinders and compression came up to 420 on one, 470 and 480 on others. I'm don't know what the compression spec is for this engine, but if someone knows and could share, that would be great. The injectors all looked clean, no carbon or discoloration. They still want to look at the turbo. I am now thinking worst case and thinking bad rings, worn cylinders. I bought the boat at a good price, but I didn't steal it and it was a stretch for me. I am thinking that I now need a rebuild, rebuilt short block or something along these lines. I don't want to repower with a new engine, since I don't want that bill, or have to mess with stringers and shaft angles, etc. I think I'm still looking at a $15 - $20K bill....ugh. Anyway, any thoughts? What would you do, if you were me? Btw, the previous owner, by way of the broker said he didn't have an oil consumption problem...hmm. I'm thinking of asking them (broker/previous owner), if they want to do the right thing and split the cost, if it turns out that I need a rebuild. Again, thoughts.



I hope everyone is enjoying the holiday and have a Merry Christmas!

Merry Christmas,
Boatdiesel.com is your friend.

[Compass790]

I dont know your engine but if it has an aircleaner check that or try running with it removed. Worked on a 75hp Cat that sucked a helluva lotta oil due to blocked air-cleaner. We trial ran it without the air-cleaner & problem went away. Was pulling too much vaccuum & sucking oil up from crankcase. Hope your fix is as simple.